A201085 Number of -5..5 arrays of n elements with first and second differences also in -5..5.

11, 91, 587, 3899, 25935, 172767, 1150785, 7664735, 51049977, 340013811, 2264635877, 15083431015, 100461998355, 669119172909, 4456615247095, 29682932959083, 197700824478473, 1316770685524945, 8770246875470677

Offset: 1

Author

R. H. Hardin Nov 26 2011

Keywords

• nonn

Comments

Column 5 of A201088

Examples

			Some solutions for n=5
.-1....1....3....4....2...-3....0...-3....2....2...-2....2....0...-5...-4...-3
..2....5....4....1....1...-4....1....0....5....2....3....0....1...-3...-5...-4
..2....4....4...-1...-3...-4...-3....0....4....5....5...-1....1...-4...-2...-3
.-2....1....1...-5...-5....1...-4...-1....2....3....3....1....1....0....1...-3
.-3....0...-2...-4...-3....5...-3....1....1...-2...-2....1....4....5....3....2
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 7*a(n-1) -6*a(n-2) +23*a(n-3) +13*a(n-4) -a(n-5) +2*a(n-6) -59*a(n-7) -102*a(n-8) -8*a(n-9) +92*a(n-10) +95*a(n-11) -18*a(n-12) -41*a(n-13) +36*a(n-14) +33*a(n-15) -49*a(n-16) -124*a(n-17) -69*a(n-18) +14*a(n-19) +88*a(n-20) +53*a(n-21) -18*a(n-22) -11*a(n-23) -2*a(n-24) -2*a(n-25) +8*a(n-26) +2*a(n-27) -10*a(n-28) -4*a(n-29) +8*a(n-30) +3*a(n-31) +2*a(n-32) +3*a(n-33) -a(n-34)